A/T Cooler Hose - Blockage Inspection

NO.:
21-06-93

GROUP:
Transmission

DATE:
Mar. 26, 1993



SUBJECT:
Transmission Cooler Service



MODELS:

1993 (AN) Dakota/Dakota Sport
(AB) Ram Van/Wagon
(AD) Ram Pickup/Ramcharger/Ram Cab Chassis
(ZJ) Grand Cherokee/Grand Wagoneer
(XJ) Cherokee
(YJ) Wrangler


DISCUSSION:


When servicing an automatic transmission for any failure, it is extremely important to always check the transmission cooler circuit for blockage. Visually inspect the cooler lines for proper routing and any signs of damage. Also, perform the flushing procedure and cooler flow test outlined in the service manual. The flush procedure performs two functions:

1. It assures that any contamination that may have accumulated in the cooler is not pumped into the transmission upon start up.

2. It may eliminate a blockage in the cooler.

The cooler flow test should be performed at both cooler lines to assure that there is no blockage internal to the transmission, or in the external cooler or lines. If flushing does not eliminate external blockage, the cooler (if available separately) or the radiator will have to be replaced.


Failure to identify a blocked cooler circuit can lead to a repeat failure. Fluid from the cooler travels back to the transmission and lubricates the gear train and internal rotating components. If the cooler is restricted, there may be little or no lubrication pressure in the transmission, which will lead to transmission failures.


POLICY: Information Only